Correct Answer: 3,000

Solution : Let the cost price be denoted as CP, the mark price be MP and the selling price be SP.
Let CP be Rs. $x$.
Profit = 60%
SP = CP + Profit = $x$ + 60% of $x$
= $x + 0.6x$
= $1.6x$
MP = Rs. 6,000
Discount = 20% of 6000 = $\frac{20}{100} × 6,000$ = 1,200
SP = MP – Discount = 6000 – 1200 = 4,800
Now, $1.6x = 4,800$
$x$ = $\frac{4800}{1.6}$
= Rs. 3,000
Hence, the correct answer is 3,000.